Ichabod reneges on his promise to dispose of Washington's too powerful Bible-secret safely, recreating the map from memory. With Sin-eater henry's help, he retrieves Katrina from Purgatory. Instead of triumphing over evil, they find themselves trapped in vines and Moloch's plan, as the demon had an undercover agent they never suspected: Jeremy, who survived buried alive for centuries and switched loyalty to his demonic savior's hell side in human, yet supernatural guise, out on convoluted, apocalyptic vengeance.
The battle between good and evil comes to an explosive head.
- In the woods, Moloch commands his minions to rise. A Horseman rides as there's an eclipse. Henry Parish wakes from his vision.
Ichabod is standing on the shore on a bright sunny day when he thinks he sees Katrina. He follows her back to a Civil War re-enactment. At first he thinks he dreaming, until a red head tells him "dude, relax." He's excited they sell clothing there. He gets a call from Henry.
Back at the cabin, Jenny Mills assesses Ichabod's new clothes, same as his old clothes. She asks if he'll be getting rid of his coat. "And risk it be worn ironically by purveyors of an artisanal marmalade who discovered it at a local thrift shop, I thank you, no," Ichabod says.
Abbie is about to go see Irving at the station, when Henry arrives and announces that he thinks that today Moloch is going to attempt to raise Hell on earth.
He saw Moloch surrounded by four white trees and he was raising a creature with a taloned hand from the dirt. He describes the Horseman, the second of the four, War. There is going to be a solar eclipse today.
Jenny mentions it's the 13 year anniversary, to the date, of when she and Abbie saw Moloch in the forest.
Abbie arrives at the station to find Irving has already been transferred upstate. He left a book for her with a note to check the marked pages.
Abbie returns to the archives, where Ichabod has found something in Washington's Bible saying a spell cast upon the dirt where the second Horseman will rise might prevent him from rising.
All the witches they know are dead, except Katrina. Ichabod reveals the map he drew to purtagory. He assures Abbie he wasn't going to use it without her.
Ichabod points to lines on a map and recalls Washington's words about a township that's a doorway between worlds.
Frank has Knapp's datebook, revealing meetings with Corbin. Abbie wants Jenny to go through the tape.
Jenny pulls her aside, incredulous that Abbie prepared to confront Moloch. But Abbie is ready to face him to reclaim their lives.
Jenny is worried about losing Abbie, but Abbie assures her she has to take on her role as a Witness and she'll be safe.
Abbie, Ichabod and Henry head to the spot in the woods that they think leads to purgatory. Ichabod expects to be able to find her in the church she visits every day. Henry warns them not to eat or drink anything while they're there or they'll become trapped.
Ichabod has an incantation from Washington's things to open the door from both sides. Henry reminds them to stay strong together over there. They recite the incantation and a mirror appears in the forest then shatters, revealing a hallway to the other side. They take hands then enter.
Abbie wakes up in the cabin with a bandage on her forehead. Sheriff Corbin and Andy Mills come in from the other room to check on her. They tell her she was in training at Quantico when she was knocked out in a line of fire exercise, which explains her confusion and memory loss.
She's thrilled to see Corbin again and hugs him. "I'm supposed to remember something," she says.
Ichabod finds himself outside a university in England. Inside, his father congratulates him for his bravery in America and says that he's been granted a full professorship. Ichabod remembers his father disavowing him after he sided with the Americans, but his father says that's ridiculous and hugs him. He calls for drinks.
At the cabin, Abbie is sitting down in front of apple pie a la mode like she and Corbin used to share. Corbin and Andy dig in when Corbin says it's like old times. Abbie remembers Crane tells her they can't go back to the way things were. Abbie stands up, saying it isn't real. Her pie runs with blood.
Corbin chases after her. She sees Andy in his resurrected battered form and Corbin holding his severed head, then falls out the cabin door.
Back with his father, Ichabod remembers talking to Abbie about his father's disapproval. Ichabod realizes it's a dream.
His father turns into a demon and roars at him.
Listening to Corbin's tapes, Jenny finds a reference to a flyer Knapp had for an old church that he thinks holds answers.
Back in Purgatory, it's an all out creep show, as Ichabod is surrounded by people with no faces in a dark wood. He finds Abbie lying facedown in the forest. To reassure each other that they're the real deal -- she asks what she taught him after they trapped the Horseman. He extends his hand for a fist bump.
They make their way to the church as disfigured lost souls crawl along the ground and walls, seeking redemption.
They find Katrina in the church and give her the fast 411, but she says she can't leave Purgatory without forgiveness. The only way her soul can leave is if another takes her place. She begs them to leave before they're all trap.
Ichabod offers, but Abbie says she has to do it to finally face Moloch. He argues, but she's resolute, even though her staying essentially fulfills Moloch's prophecy.
Katrina gives Abbie an amulet to protect her from Moloch and promises to return after they've stopped War. Ichabod starts to vow he'll return, but she's sure he will. "Remember our bond, faith," he says.
Ichabod teaches her the phrase to repeat, the doorway opens and they end up on the other side, where Parish is waiting.
In the forest, Moloch comes for Abbie, telling her there's no escape. She picks up a branch to take him on, but he lifts her off her feet by her throat. She rips the amulet off her neck and presses it into his skin, burning him. He drops her and she runs off.
Back in the forest, Katrina starts about trying to locate where the second Horseman will emerge. Her power is weak from lack of use, but she's able to determine the direction.
Meanwhile, Jenny arrives at the same church from Corbin's tape. It's boarded up.
Ichabod, Katrina and Parris reach the four white trees.
Jenny listens to Corbin's tapes, in which he wonders why someone would want to hide an abandoned church's name. As the eclipse begins, Jenny sees a fallen sign on the ground and uncovers it. She gets in her car and leaves Abbie a message saying she figured out Moloch's warning. "The Saint's name is a sign -- he meant it literally, so whatever you do you can't --"
She's interrupted by a gunshot through her SUV window. The headless Horseman blocks her path and fires again. Her SUV flips over repeatedly, finally coming to a stop with her upside down inside.
Back in Purgatory, Abbie finds herself in a lifesize vesion of the dollhouse she and her sister used to play. She finds young versions of herself and Jenny.
The young version of herself tells her the reason she can't remember what happened after they saw Moloch in the woods is because he removed her memory, so she wouldn't know the truth.
In the woods, Katrina says there's nothing in the ground where the Horseman supposedly is.
Parish assures them the Horseman is there. He asks Ichabod if he knows the etymology of the word apocalypse: "to disclose or reveal."
Then he flings Ichabod and Katrina each against a white tree with his power and holds them there. He mocks Ichabod for being so easy to manipulate, and Abbie for wanting to believe there's a purpose to her pain.
Katrina realizes he gave her the idea to find the sin eater, a message which she relayed to Abbie. He reminds them about times he hinted about his identity, including when he was rhapsodizing about his love for good crossword puzzles ability to mislead and trick.
Parish tells them the second Horseman rose over a decade ago in the forest, and waited all this time to take form.
Back in Purgatory, young Abbie tells Abbie that it wasn't an accident Moloch was in the forest that day, and there was a reason they were sent there.
Abbie still can't remember, so young Abbie helps her remember seeing Moloch bring the second Horseman into the world -- Henry Parish.
Katrina compares Parish to Abraham, who was mortal before he became Death. "Only half mortal. I am, after all, what you made me -- Mother and Father," Parish says.
He was killed by his mother's own coven and left to wither in a plain pine box. He takes out a knife and cuts his hand, bleeding on the ground, reminding them of the power of his blood. The pine box where he was buried is revealed in the dirt.
Ichabod remembers how his blood killed his son's Golem, and realizes Parish knew it would.
He didn't die, he laid in the box for two centuries, feeding on the vines that crept in, cursing those who abandoned him, until his "true father" came to rescue him.
Ichabod speaks to his son, calling him Jeremy, telling him Moloch is a prince of lies. Parish/Jeremy explains God sent a witness to stop him 13 years ago, but she wasn't strong enough and they defeated her, as they have again now.
In Purgatory, Abbie sees Parish is the Second Horseman and tries to figure a way out, as her young self explains Purgatory is her home now.
Henry/Jeremy explains he got his name when he wandered through the forest and the first place he saw was the church. We see the sign that Jenny found facedown: It says "St. Henry's Parish."
Ichabod and Katrina try to reach Jeremy, but can't. "Now that the two Witnesses are separated, there is nothing to stop us breaking the second seal, and fulfilling the promise made long ago to an old friend," he says.
The Horseman/Abraham rides up and takes Katrina.
With his powers, Jeremy puts Ichabod in his old box in the ground. He removes the second seal from a leather pouch and breaks it over him.
"War isn't coming to Sleep Hollow, it's been here waiting all along. And now, it begins," Jeremy says. "Good bye, father," he says, as the casket in the ground slams shut over a screaming Ichabod.